Question

a student has some $1 and $5 bills in his wallet. he has a total of 15 bills that ar worth $47. how much of each type of bill does he have

Answer 1

a = 7 ($1)

b = 8 ($5)

Explanation:

a + b = 15 | (-)

1a + 5b = 47

- a - b = - 15

a + 5b = 47

------------------ +

-a + a - b + 5b = - 15 + 47

4b = 32

b = 32 : 4

b = 8

a = 15 - 8 = 7